Automatic safety fire-alarm



(No Model.) '2 sheets-sheen 1.;

A. B. GRISWOLD & J. lVI. BRADBURY.

AUToMATIe SAFETY PIRE ALARM.

No. 422,205. Patented Feb. 25, 1890..

n l I l1N 0 Model.) 2 sheets-sheen 2.

A. B. GRISWQLD 22 J. M. BRADBURY.

AUTOMATIC SAFETY FIRE ALARM.

No. 422,205. Patented Feb. 25, 1890.l

N. Pneus. Phaea-Lixhagmpm. washinnm nc which'is secured in the main casing A on a pivotal lever or index-finger G, which latter is pivoted at C, and is held from being accidentally displaced by frictional contact ou the pivot which supports the coil and indicater-finger G at g. Below the lower point of the indicator-finger G is a graduated scale H,

which enables the user of the fire-alarm to adjust the outer free end f of the coil F to the proper p osition opposite the vertical gravity-lever E within the main casing A.

The cover of the casing A is removable, and can be taken off to adj ust the lever G on the graduated scale, or the lever G may be placed on the outside of the rear of the box, all of which will be readily understood by those skilled in the art. f

Near the outer free end f of the coil F the casing A. is provided with a thermometric scale l, which also facilitates the nice adj ustment of such outer free endb The cog-wheel J is pivoted to the interior of the casing A at J', and is actuated by any suitable clock mechanism, (not shown,) and meshes with a wheel on the cscapement-wheel arbor k in such a manner that as soon as the rod b', which corresponds to the pendulum, is released it is allowed to vibrate Sufiicient power to overcome friction is imparted by the wheel J, which receives its power as above described.

Inside ot the casing A. we sometimes design to use a bell-crank L, which is pivoted at L', and has secured toits upper end a wire l, which operates a bell m, as is clearly shown in Figs, 2 and 3. When this bell-crank is used, the same gravity-lever E, in falling strikes the horizontal lever D, and is provided with a pin e2 on its rear face, which also strikes the lower free end of the bellcrank L, and rings the bellm at the same time that it sets the gong a to ringing inside of the case A.

The spring F may be made in any desired shape and of' any desired compound or combination of metals which expand unequally` when heated. Ve prefer, however, to make it in the shape of a coil-spring, leaving the l outer free end f to move up and down as the coil is contracted or expanded by heat or cold., lt will be understood that in this parsion of the metals by heat to give the alarm in case of fire.

XVe do not wish to be understood as limiting ourselves to the use of clock-work or any combination of levers and cog-wheels or pulleys, as an electric battery could be used just as well, and an electric bell might be used instead of 'the bell shown and described, which would serve the purpose of the one herein shown and described, after it had once been set off, without departing from the spirit of our invention.

We do not claim to be the inventors of the clock-work mechanisml nor of electric bells,

as either of these` devices is old and can be bought anywhere in open market, and either might be used to secure the same general advantages in combination with our construction without departing from the spirit of our invention.' This device may also be used as a burglar-alarm by attaching a simple device to the free end f of the coil F in such a manner that the opening of a door or raising of a window would raise such free end and release the vertical gravity-weight E, and thus give an alarm, without departing from the spirit of. our invention.

Having now described our invention1 what we desire to secure by Letters Patent, and

what we therefore claim, isd

1. The combination of a casing containing an alarm-signal and an eccentric gravity-lever supported in a suspended position by an expanding metallic strip, with a second lever pivoted and located in front of the said gravity-lever, and which controls the alarm or signal, and which is operated by the first lever when released, all constructed and combined to operate substantially as speciiied.

2. The main casing provided with suitable fire-alarm mechanism and a graduated scale, in combination with an eccentrically-pivoted gravity-lever and an expanding metallic strip, which is rigidly connected with a finger G, and which supports the gravity-lever in its suspended position and holds it in that position ata point adjacent to the graduated scale, and av graduated scale for said finger G, all constructed and combined to operate substantially as described, -whereby the tineness of the adjustment of the metallic strip to the eccentrically-pivoted gravity-lever may be determined, substantially as and for the purposes specified.

3. The combination of the main casing provided with the eccentric gravity-levers, the v operating mechanism for the alarm, and a metallic strip mounted on a pivotal support,

which is held in its normal position by frictional contact with the pivotal support, and a graduated scale and an indicating-finger, said finger being rigidly secured to themetallic strip at its supported end, and moving therewith the free end ot said metallic strip, supporting in a suspended position the eccentric ticular instance we depend upon the eXpanpivoted as described and supported in a suspended position by an elastic movable bar,

` with mechanism for trppingthe same and our invention We hereunto set ouf hands in setting off the alarm by the expansion of the the presence of two subscribing Witnesses.

metallic strip F Within the main easing, and ALANSON B. GRISWULD. the additional supplemental tripping meoh- JOHN M. BRADBURY. 5 ansm for mechanically releasing it, substan- Witnesses:

tially as and for the purposes specified. f PETER MENZIES,

In testimony that we claim the above as J. E. SHUOKHART. 

